关于克隆的英语作文 写一篇关于克隆的文章，要有反对克隆的原因和赞同克隆的原因，还要有自己的观点
westhusin＇s experience with cloning animals leaves him upset by all this talk of human cloning. in three years of work on the missy project, using hundreds upon hundreds of dog＇s eggs, the a&m team has produced only a dozen or so embryos (胚胎) carrying missy＇s dna. none have survived the transfer to a surrogate (代孕的) mother. the wastage of eggs and the many spontaneously aborted fetuses (胎) may be acceptable when you＇re dealing with cats or bulls, he argues, but not with humans. "cloning is incredibly inefficient, and also dangerous," he says.
even so, dog cloning is a commercial opportunity, with a nice research payoff. ever since dolly the sheep was cloned in 1997, westhusin＇s phone has been ringing with people calling in hopes of duplicating their cats and dogs, cattle and horses. "a lot of people want to clone pets, especially if the price is right," says westhusin. cost is